import React, { Component } from 'react';
import './index.css';

export default class Item extends Component {
  
  state = { mouse: false } // 标识鼠标移入、移出

  // 鼠标移入、移出的回调
  handleMouse = (mouse) => {
    return () => {
      this.setState({ mouse })
    }
  }

  // 勾选、取消勾选某一个todo的回调
  handelCheck = (id) => {
    return (event) => {
      this.props.updateTodo(id, event.target.checked)
    }
  }

  // 删除一个todo的回调
  handleDelete = (id) => {
    if (window.confirm('确定删除吗?')) {
      this.props.deleteTodo(id)
    }
  }

  render () {
    const { id, name, done } = this.props;
    const { mouse } = this.state
    return (
      <li style={{backgroundColor: mouse ? '#ddd' : 'white'}}
        onMouseEnter={this.handleMouse(true)}
        onMouseLeave={this.handleMouse(false)}
      >
        <label>
          <input type="checkbox" checked={done} onChange={this.handelCheck(id)} />
          <span>{name}</span>
        </label>
        <button onClick={()=> this.handleDelete(id)} className="btn btn-danger" style={{ display: mouse ? 'block' : 'none'}}>删除</button>
      </li>
    )
  }
}